Exercising in the morning or afternoon beats nighttime workouts for diabetes prevention

BOSTON — Engaging in physical activity during the morning or afternoon may be more beneficial than evening exercises when it comes to preventing diabetes, a new study explains. These findings come after another team found that morning exercise is also the most effective time for weight loss.

The research indicates that daytime physical activity displays a connection to a reduced risk of Type 2 diabetes, irrespective of an individual’s age, income, or educational background. However, evening exercise didn’t show a statistically significant link to diabetes risk, according to the results published in the journal Diabetologia.

Prior studies highlighted that afternoon exercises, as opposed to evening workouts, had a lower risk associated with premature death in comparison to morning exercises. Yet, the correlation between such activity timings and Type 2 diabetes has been understudied. Dr. Caiwei Tian from Harvard University and Dr. Chirag Patel from Harvard Medical School, along with their team, investigated the link between morning, afternoon, and evening exercises and Type 2 diabetes risk.

The study involved over 93 British participants, averaging 62 years of age, without a history of Type 2 diabetes. These participants wore wrist accelerometers for a week. From the data gathered, the researchers estimated the metabolic equivalent of task (MET) – a standard metric for physical activity. They elaborated that MET-hour activity encompasses all forms of activities tracked by the accelerometer throughout the day, including chores, walking, and intense exercises.

Man lifting weights is tired, has headache from exercise
Photo by Sander Meyer on Unsplash

The researchers categorized METs into three periods: morning (6 a.m. to 12 p.m.), afternoon (12 p.m. to 6 p.m.), and evening (6 p.m. to midnight). They also considered exercise intensity levels: moderate-to-vigorous physical activity (MVPA) and vigorous physical activity (VPA) concerning Type 2 diabetes.

Their findings showed the protective effects of physical activity. Every one-unit increase in MET corresponded to a 10-percent and nine-percent decrease in the risk of Type 2 diabetes during the morning and afternoon, respectively. Again, evening exercises did not exhibit a significant relationship with diabetes risk.

The team speculates that lifestyle factors, such as sleep duration and diet, might impact the volume of exercise undertaken during different times of the day, subsequently affecting its role in diabetes risk. On adjusting for these lifestyle factors, the associations between MET-hours and different times of the day became sharper.

Dr. Tian notes that while the consistency of MET-measured activity wasn’t tied to Type 2 diabetes, its intensity was. Both MVPA and VPA correlated with a reduced diabetes risk throughout the day. Lastly, the researchers highlighted that their study is pioneering in evaluating the influence of activity consistency.

“The consistency or routine of physical activity was not strongly associated with Type 2 diabetes. In other words, individuals who exercise a smaller amount of time more frequently are at no lesser risk for diabetes than individuals who exercise the same total amount, but with less of a routine,” the study authors say in a media release.

“Our findings support that total physical activity but not its consistency over the week may be an important factor impacting Type 2 diabetes risk. The timing of activity may play a role in mitigation of diabetes risk,” the research team concludes.

“Our study showed an association with diabetes risk between morning and afternoon versus evening physical activity. The findings also suggest it is helpful to include some higher intensity activity to help reduce the risk of developing diabetes and other cardiovascular disease.”

South West News Service writer Stephen Beech contributed to this report.

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